Ishikawa Diagram
DE: Ishikawa-Diagramm
A cause-and-effect diagram (fishbone) for root cause analysis.
Detailed Explanation
The Ishikawa diagram (also called fishbone diagram or cause-and-effect diagram) is a tool used to identify the root causes of quality problems. The effect (problem) is placed at the 'head' of the fish, and potential causes branch off the 'spine' organized by category.
Common cause categories for manufacturing use the 6 Ms: Methods, Machines, Materials, Manpower, Measurement, and Mother Nature (Environment). For services, the 4 Ps are common: Policies, Procedures, People, and Plant (Technology). Categories should be adapted to the context.
The diagram is created collaboratively during a brainstorming session. The team identifies all possible causes within each category, then uses techniques like the '5 Whys' to drill down to root causes. It is a powerful visual tool that ensures the team explores all potential cause areas systematically.
Key Points
- Also called fishbone or cause-and-effect diagram
- Problem at the head, causes branching off by category
- 6 Ms for manufacturing: Methods, Machines, Materials, Manpower, Measurement, Environment
- 4 Ps for services: Policies, Procedures, People, Plant
- Created collaboratively through brainstorming
- Combined with '5 Whys' to reach root causes
Practical Example
A project is experiencing frequent deployment failures. The team creates an Ishikawa diagram with categories: Process (no deployment checklist), People (insufficient training on new tools), Technology (outdated CI/CD pipeline), Environment (different configs between staging and production). They identify the root cause: environment configuration drift. Solution: implement infrastructure-as-code to keep environments synchronized.
Tips for Learning and Applying
Adapt categories to your industry and context
Use brainstorming with the full team for comprehensive cause identification
Combine with the '5 Whys' technique to drill past symptoms to root causes
Focus on the most impactful root causes — do not try to solve everything at once
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